Reply to A Walker and B Walker

Department of Nutritional Sciences
Faculty of Medicine
University of Toronto
150 College Street
FitzGerald Builing, Room 340
Toronto, Ontario
Canada M5S 3E2
E-mail: cyril.kendall{at}utoronto.ca

Dear Sir:

Walker and Walker, in their comments about our editorial accompanying the article by Gross et al (1) on the consumption of refined carbohydrates and disease, note that preventive strategies should begin with the young and that developing nations are far from free of the problems of overconsumption, especially affluent populations in urban centers. They also mention that certain subgroups may be more favored health-wise because of their particular daily habits and practices. Vegetarians are singled out as an example of a group who have age-adjusted lower rates of coronary heart disease, stroke, and all-cause mortality (2). This example is relevant at a time when Gary Fraser and friends have published their assessment of the effect of vegetarian diets on chronic disease and longevity (3). They concluded that a Californian Seventh-Day Adventist vegetarian lifestyle including diet, exercise pattern, and tobacco and alcohol use results in a marked increase in longevity. For men aged >30 y, life expectancy was 7.28 y longer than for the general population; for women, life expectancy was 4.42 y longer (4). A more modest effect was found in an Oxford study of British vegetarians, which also showed a greater life expectancy in vegetarians than in nonvegetarians. Vegetarians, and certainly vegans (5), tend to weigh less than their omnivorous counterparts, and their incidence of diabetes has been reported to be lower. Are vegetarians spared because they consume a greater amount of unrefined traditional carbohydrate foods, which have a lower glycemic index, or do they simply eat fewer calories than they expend? Certainly, the most recent analysis of the Nurses' Health Study again showed a protective effect of both cereal fiber and a low glycemic index in reducing the risk of diabetes after adjustment for body weight and exercise (6).

Walker and Walker mention that diabetes is on the rise in urban and suburban Africa. Lack of exercise is noted as one reason for this change, but the shift to a more Western dietary pattern, which is characterized by foods with higher glycemic indexes, is another reason.

Unfortunately, without more research and education globally, these changes in human health are inevitable because it appears that we have been given what we have asked for: an abundant supply of inexpensive food and a lifestyle that requires minimal energy expenditure. The industrial sector has simply done what we have paid them to do. Since when has money been made on food that is "good for you" but that does not "taste good"? What automobile or kitchen appliance was ever sold because "you have to expend more energy to use this model than the previous one"? Taste, ease and speed of food preparation, and labor-saving devices of all kinds are the order of the day. We should not expect citizens of less industrialized nations to have goals different from our own. In fact, human migration patterns indicate a move from countryside to cities and from less to more industrialized societies.

Perhaps we should reflect on the lives of many modern-day humans, who spend much of their time hunched over word processors, who tend to eat high-calorie comfort foods and foods with high glycemic indexes, and expend little time on exercise. Are we setting a good example to the developing world? Is eating less-processed foods and working out at the gym the whole answer, or is there more to life (and nutrition)?

ACKNOWLEDGMENTS

DJAJ has served as a consultant to Solale (St Louis) and to the Almond Board of California for the past 5 y, has received honoraria from Oldways Preservation Trust (Boston) and the Almond Board of California, and is on the Scientific Advisory Board of Loblaws Supermarket, Sanitarium Company (Sydney, Australia), Herbalife International (Century City, CA), Nutritional Fundamentals for Health (Montreal), Pacific Health Laboratories Inc (Matawan, NJ), and the California Strawberry Commission. CWCK has received honoraria from the Almond Board of California.

REFERENCES

1. Gross LS, Li L, Ford ES, Liu S. Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessment. Am J Clin Nutr 2004;79:774-9.
2. Key TJA, Thorogood M, Appleby PN, Burr ML. Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up. BMJ 1996;313:775-9.
3. Fraser GE. Diet, life expectancy and chronic disease: studies of Seventh Day Adventists and other vegetarians. New York: Oxford University Press, 2004.
4. Fraser GE. Diet, life expectancy and chronic disease: studies of Seventh Day Adventists and other vegetarians. New York: Oxford University Press, 2004:50.
5. Fraser GE. Diet, life expectancy and chronic disease: studies of Seventh Day Adventists and other vegetarians. New York: Oxford University Press, 2004:32.
6. Schulze MB, Liu S, Rimm EB, Manson JE, Willett WC, Hu FB. Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women. Am J Clin Nutr 2004;80:348-56.